1. Field of the Invention
The present invention relates to a display drive apparatus capable of carrying out gradation display by a frame rate control (FRC) method, and a display apparatus including the same.
2. Description of the Related Art
Conventionally, a frame rate control (FRC) method (“FRC drive”) has been known as one of the methods for carrying out gradation display on a display apparatus such as a liquid crystal display. The FRC method is a method in which a display drive apparatus capable of carrying out display in predetermined gradations carries out display in multiple gradations more than the predetermined gradations. This FRC method is a method in which several frames are set as one cycle, and a halftone is obtained by temporally changing gradations of respective pixels in this one cycle.
Here, in FRC drive, flicker is easily caused at the time of carrying out halftone display. Therefore, in FRC drive, it is ideal to carry out display in multiple gradations by replacing data of frames and at a display position, and to suppress flicker as much as possible. However, there occur images in which flicker is easily brought about by driving at any means, and it is generally thought to be difficult to suppress flicker in every image.
As means for suppressing such flicker, there have been proposed a method in which a large number of look-up tables are provided in advance, drive display is carried out by randomly selecting a look-up table. In addition, a method has been proposed in which FRC patterns based on which flicker is hard to occur are prepared before and after frame frequency conversion with respect to input gradation data, and display drive is carried out in accordance with these FRC patterns, and the like.
Here, in the method in which look-up tables are provided in advance, or in the method in which FRC patterns are generated based on which flicker is hard to occur, the effect of preventing flicker from occurring is high. However, a storage unit dedicated for storing the look-up tables is required, or it is necessary to prepare FRC patterns before and after frame frequency conversion, which is more likely to make a circuit structure and a drive method complicated.